<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8" />
  <meta http-equiv="X-UA-Compatible" content="IE=edge" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <link rel="stylesheet" href="./css/index.css" />
  <title>记事本</title>
</head>

<body>

  <!-- 主体区域 -->
  <section id="app">
    <!-- 输入框 -->
    <header class="header">
      <h1>小黑子记事本</h1>
      <input placeholder="请输入任务" class="new-todo" / v-model="value">
      <button class="add" @click="get">添加任务</button>
    </header>
    <!-- 列表区域 -->
    <section class="main">
      <ul class="todo-list">
        <li class="todo" v-for="(item, index) in list" :key="item.id">
          <div class="view">
            <span class="index">{{ index + 1}}.</span> <label> {{ item.name }} </label>
            <button class="destroy" @click="fn(item.id)"></button>
          </div>
        </li>
      </ul>
    </section>
    <!-- 统计和清空 -->
    <footer class="footer" v-show="list.length > 0">
      <!-- 统计 -->
      <span class="todo-count">合 计:<strong> {{ list.length }} </strong></span>
      <!-- 清空 -->
      <button class="clear-completed" @click="getFn">
        清空任务
      </button>
    </footer>
  </section>

  <!-- 底部 -->
  <script src="https://cdn.jsdelivr.net/npm/vue@2.7.14/dist/vue.js"></script>
  <script>

    const app = new Vue({
      el: '#app',
      data: {
        list: [
          { id: 1, name: '跑步一公里' },
          { id: 2, name: '打球一小时' },
          { id: 3, name: '游泳100米' },
        ],
        value: ''
      },
      methods: {
        fn(id) {
          this.list = this.list.filter(item => item.id !== id)
        },
        get() {
          if(this.value.trim() === '') return alert('不能为空')
          this.list.unshift({
            id: +new Date(),
            name: this.value
          })
          this.value = ''
        },
        getFn() {
          this.list = []
        }
      }
    })

  </script>
</body>

</html>